Schwinghammer T L
Am J Hosp Pharm. 1981 Dec;38(12):1976-8.
Drug-drug interactions of cimetidine and possible mechanisms of interaction are discussed. Cimetidine has several actions in vivo that may result in drug-drug interactions. By decreasing acid secretion into the stomach, cimetidine increases the pH of the gastric contents. This may lead to decreased absorption of drugs that require a lower pH for dissolution, or increased absorption of drugs whose absorption is normally decreased by acid inactivation in the stomach. Cimetidine also reduces hepatic blood flow significantly and inhibits microsomal metabolism of drugs inactivated by this system. Both of these actions impair inactivation of numerous drugs. Cimetidine's increase of gastric pH has not been shown to result in clinically important drug-drug interactions. Cimetidine's effects of hepatic metabolism and blood flow are clinically relevant, and several interactions are attributable to them.
讨论了西咪替丁的药物相互作用及其可能的相互作用机制。西咪替丁在体内有多种作用，可能导致药物相互作用。通过减少胃酸分泌进入胃内，西咪替丁提高了胃内容物的pH值。这可能导致需要较低pH值溶解的药物吸收减少，或者通常因胃酸失活而吸收减少的药物吸收增加。西咪替丁还会显著减少肝血流量，并抑制该系统灭活的药物的微粒体代谢。这两种作用都会损害多种药物的失活。西咪替丁增加胃内pH值尚未被证明会导致具有临床重要性的药物相互作用。西咪替丁对肝代谢和血流量的影响具有临床相关性，并且有几种相互作用可归因于此。
